Cafe

When you picture the lowest levels of the food chain, you might imagine herbivores happily munching on lush, living green plants. But this idyllic image leaves out a huge (and slightly less appetizing) source of nourishment: dead stuff. John C. Moore details the "brown food chain," explaining how such unlikely delicacies as pond scum and animal poop contribute enormous amounts of energy to our ecosystems.

When wolves were reintroduced to Yellowstone National Park in the United States after being absent nearly 70 years, the most remarkable "trophic cascade" occurred. What is a trophic cascade and how exactly do wolves change rivers? George Monbiot explains in this movie remix.

This week marks the 178th anniversary of Darwin's first exploration of the Galapagos Islands. This volcanic archipelago is one of the most biodiverse and unique places on the planet, with species that have remarkably adapted to their environment. Through observing the animals, Darwin made key insights that informed his theory of evolution. Here's a short documentary that captures the 10-day expedition: More info